[PATCH] sparc64: fix set_page_count merge clash

Merge clash will have broken sparc64. Synch up its online_page
implementation with powerpc, which was identical until the
set_page_count removal.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>